1. Field of the Invention
The present invention relates to the use of 2,4-di(lower alkyl)-1,2,4-thiadiazolidin-3,5-dione compounds as load-carrying additives for functional fluids such as lubricants and hydraulic fluids.
2. Description of the Prior Art
The employment of chemical additives in lubricants, hydraulic oils and similar functional fluids to improve the overall load-carrying characteristics of the fluid is well known. Probably, the most commonly employed load-carrying additives are the zinc dialkyl and diaryl dithiophosphates. However, for many applications it is necessary to employ ashless formulations (i.e., formulations that leave substantially no ash residue upon evaporation or combustion). In such instances, these zinc-containing compounds are not satisfactory.
Many load-carrying additives have, alternatively, been found which have this desired ashless characteristic. However, there is still a need in the art to find more suitable ashless additives. To meet that need is the primary object of this invention.
The 2,4-di(lower alkyl)-1,2,4-thiadiazolidin-3,5-diones of the present invention have been employed as agricultural chemicals such as foliar and soil fungicides. See U.S. Pat. No. 3,374,240 which issued to Ottman and Hooks, Jr. on Mar. 19, 1968. However, this reference does not teach or suggest the present inventive use.